North Korea’s Nuclear Weapons, Japan’s Bind

Members of Japan’s Self-Defense Forces during training near Mount Fuji in late August.CreditCreditTomohiro Ohsumi for The New York Times

TOKYO — Pyongyang’s recent missile launch over Hokkaido and its underground nuclear test have laid bare Japan’s Achilles’ heel: Our country’s national security policy is still woefully ill equipped for this mounting danger. The new sanctions adopted by the United Nations Security Council on Monday will hardly limit Japan’s exposure.

North Korea’s latest provocations pose an unprecedented threat. Even during the Korean War in the early 1950s, Japan, as a rear support base for United States forces, was somewhat insulated; today, it is in the same theater as South Korea, also on the front lines. Any American military strike against North Korea would likely trigger retaliatory measures against Japan.

Japan is in a terrible predicament: Highly exposed but with very few options, military or diplomatic, to help itself.

Its defense ministry plans to double, to eight, the number of ships equipped with the Aegis missile-defense system. But the new fleet won’t be operational before 2021. Even if Japan also acquires the land-based Aegis Ashore system, as it is contemplating doing, none of this additional capacity could offer it enough protection against North Korea’s increasingly lethal missiles — much less deter North Korea from further developing its own arsenal.

This is one reason Itsunori Onodera, the new defense minister, has been making a case for developing Japan’s offensive capabilities, so that it could strike military bases in North Korea, perhaps even preemptively. But such a move faces numerous obstacles — financial, tactical and strategic.

No budget decision for such capabilities is expected to even be made until at least late 2018. Acquiring offensive weaponry would require redefining the terms of Japan’s existing security agreement with the United States, which relegates Japan to a purely defensive role and places all responsibility for any offensive action solely with America.

In the face of these constraints, some pundits and officials in Washington are arguing that Japan, as well as South Korea, might, and perhaps should, consider acquiring nuclear weapons themselves.

The idea is a nonstarter. According to an opinion poll conducted in June and July, only 9 percent of Japanese respondents think Japan should acquire nuclear weapons. (About 67 percent of South Koreans polled said that South Korea should get such weapons.) The nuclearization of Japan — or South Korea — would undermine nonproliferation efforts, as well as validate North Korea’s nuclear brinkmanship to date.

Given the difficulties of developing an independent military capability, Tokyo has no choice but to pursue a diplomatic solution with the help of other states — even though several multilateral efforts have failed in the past and bilateral relations between some of the main players today arguably are more fraught than ever.

Tensions are mounting between the United States and China, for example, over dominance in the South China Sea. South Korea’s decision to deploy the missile-defense system known as Thaad to protect itself from North Korea has riled Beijing, which says the system is in fact designed to track missiles from China.

Relations between Tokyo and Seoul have long been uneasy, largely because of unresolved issues from Japan’s occupation of the Korean Peninsula in the 1930s and 1940s, including about so-called comfort women, Korean women who were coerced or compelled into having sex with Japanese soldiers. And the new South Korean president, Moon Jae-in, appears to be taking a firmer stand on that question than his predecessor, who signed an agreement with Japan in 2015 hoping to finally settle the matter. It is now very difficult to imagine, for example, that Japan’s Self-Defense Forces could ever operate on South Korean soil, even to assist with, say, an evacuation after an attack by North Korea.

At the same time, however, as the threat from Pyongyang becomes more ominous, the pressing need for an effective response may suggest, even create, new diplomatic opportunities.

Prime Minister Shinzo Abe of Japan and President Trump seem to have quickly developed an intimate working relationship, and that — along with South Korea’s moves to strengthen its security ties with the United States — may allow for more effective cooperation among the three countries, despite difficulties between Japan and South Korea. This trilateralism, in turn, could form the basis for five-party talks including China and Russia, and eventually lead to the resumption of negotiations with Pyongyang as well.

The U.N. Security Council’s decision to cap North Korea’s oil imports, though a watered-down version of the penalties sought by the United States government, was significant nonetheless. For one thing, it was a reminder that coordinated action with China and Russia, which have been wary of imposing more sanctions against Pyongyang, is possible.

On this front, too, North Korea’s recent brinkmanship may have unexpectedly paved the way for new (if slim) possibilities for cooperation. Mr. Abe and President Vladimir V. Putin of Russia seem to have developed an effective line of communication, including on intractable-seeming issues, like the status of contested islands in the Pacific. And the chances for at least some measure of rapprochement between Japan and China may be growing. Building bridges with Beijing remains a loaded notion for many Japanese people, but Mr. Abe now has more clout and political capital to try, in the name of protecting Japan against the more immediate threat posed by North Korea.

The recent escalation of the North Korea crisis seems to have validated Mr. Abe’s controversial efforts to strengthen Japan’s defense posture. The Japanese public is now more open to adopting a tougher stance. The new leader of the opposition Democratic Party, Seiji Maehara, is a hawk, and under his leadership the party, traditionally an advocate of pacifism, is likely to support, if perhaps reluctantly, the Abe administration’s hard-nosed approach to security.

There is no viable military solution to the North Korea crisis. Japan, like the other main parties, must make the most of the slivers of opportunity created by the escalating threat to renew efforts at finding a multilateral diplomatic solution.

Yoichi Funabashi is chairman of the Asia Pacific Initiative, a think tank in Tokyo.